The SL pay system was established under the Federal Employees Pay Comparability Act of 1990 (FEPCA) to replace grades GS-16, 17, and 18 of the General Schedule, which were abolished. 

Positions in the SL system are classified above GS-15, but do not meet the executive criteria characteristic of the SES nor do they involve the fundamental research and development responsibilities that are characteristic of the ST pay system. However, the SL system is used for positions that meet the SES executive criteria in agencies that are excluded from the SES. The SL positions may be in either the competitive or excepted service. When advertising a vacancy for an SL position in the competitive service, there is no requirement for Government-wide recruitment. 

SUPERVISORY DUTIES

SL positions may include supervisory and related managerial duties, provided these duties occupy less than 25 percent of the position’s time. Positions in which supervisory and managerial work as defined in OPM’s General Schedule Supervisory Guide constitutes a major duty that occupies 25 percent or more of the position’s time, and most always meet the criteria for SES positions.